diff --git a/src/algorithms/tonal/vibrato.cpp b/src/algorithms/tonal/vibrato.cpp
index ccae3f611..3ad7b2474 100644
--- a/src/algorithms/tonal/vibrato.cpp
+++ b/src/algorithms/tonal/vibrato.cpp
@@ -26,7 +26,7 @@ using namespace standard;
 
 const char* Vibrato::name = "Vibrato";
 const char* Vibrato::category = "Pitch";
-const char* Vibrato::description = DOC("This algorithm detects the presence of vibrato and estimates its parameters given a pitch contour [Hz]. The result is the vibrato frequency in Hz and the extend (peak to peak) in cents. If no vibrato is detected in a frame, the output of both values is zero.\n"
+const char* Vibrato::description = DOC("This algorithm detects the presence of vibrato and estimates its parameters given a pitch contour [Hz]. The result is the vibrato frequency in Hz and the extent (peak to peak) in cents. If no vibrato is detected in a frame, the output of both values is zero.\n"
 "\n"
 "This algorithm should be given the outputs of a pitch estimator, i.e. PredominantMelody, PitchYinFFT or PitchMelodia and the corresponding sample rate with which it was computed.\n"
 "\n"
@@ -91,7 +91,7 @@ void Vibrato::compute() {
     startC.push_back(0);
   }
   for (int i=0; i<(int)pitchP.size()-1; i++) {
-    if (pitchP[i+1]>0 && pitchP[i]==0){
+    if (pitchP[i+1]>0 && pitchP[i]==0) {
       startC.push_back(i+1);
     }
     if (pitchP[i+1]==0 && pitchP[i]>0) {
@@ -138,7 +138,7 @@ void Vibrato::compute() {
       if(!frame.size()) {
         break;
       }
-          
+
       // subtract mean pitch from frame
       Real m = mean(frame, 0, frame.size()-1);
       for (int ii=0; ii<(int)frame.size(); ii++) {
@@ -181,11 +181,17 @@ void Vibrato::compute() {
       if (ext<_minExtend || ext>_maxExtend){
         continue;
       }
-    
-      for (int ii=startC[i]+frameNumber-1; ii<startC[i]+frameNumber+frameSize-1; ii++) {
+
+      int ii = startC[i]+frameNumber-1;
+      vibratoFrequency[ii] = peakFrequencies[0];
+      vibratoExtend[ii] = ext;
+      // NOTE: no need to loop over the frame, as the hopSize is 1
+      /*
+      for (int ii=startC[i]+frameNumber-1; ii<startC[i]+frameNumber-1+frameSize; ii++) {  
         vibratoFrequency[ii]=peakFrequencies[0];
         vibratoExtend[ii]=ext;
       }
+      */
     }
   }
 }
diff --git a/src/algorithms/tonal/vibrato.h b/src/algorithms/tonal/vibrato.h
index 5c6e5337f..f6ec1597b 100644
--- a/src/algorithms/tonal/vibrato.h
+++ b/src/algorithms/tonal/vibrato.h
@@ -40,8 +40,8 @@ class Vibrato : public Algorithm {
  public:
   Vibrato() {
     declareInput(_pitch, "pitch", "the pitch trajectory [Hz].");
-    declareOutput(_vibratoFrequency, "vibratoFrequency", "estimated vibrato frquency [Hz]; zero if no vibrato was detected.");
-    declareOutput(_vibratoExtend, "vibratoExtend","estimated vibrato frquency [Hz]; zero if no vibrato was detected.") ;
+    declareOutput(_vibratoFrequency, "vibratoFrequency", "estimated vibrato frequency (or speed) [Hz]; zero if no vibrato was detected.");
+    declareOutput(_vibratoExtend, "vibratoExtend","estimated vibrato extent (or depth) [cents]; zero if no vibrato was detected.") ;
       
     frameCutter = AlgorithmFactory::create("FrameCutter");
     window = AlgorithmFactory::create("Windowing");
@@ -54,8 +54,8 @@ class Vibrato : public Algorithm {
   void declareParameters() {
     declareParameter("minFrequency", "minimum considered vibrato frequency [Hz]", "(0,inf)", 4.0);
     declareParameter("maxFrequency", "maximum considered vibrato frequency [Hz]", "(0,inf)", 8.0);
-    declareParameter("minExtend", "minimum considered vibrato extend [cents]", "(0,inf)", 50.0);
-    declareParameter("maxExtend", "maximum considered vibrato extend [cents]", "(0,inf)", 250.0);
+    declareParameter("minExtend", "minimum considered vibrato extent [cents]", "(0,inf)", 50.0);
+    declareParameter("maxExtend", "maximum considered vibrato extent [cents]", "(0,inf)", 250.0);
     declareParameter("sampleRate", "sample rate of the input pitch contour", "(0,inf)", 44100.0/128.0);
   }
 
diff --git a/test/src/unittest/tonal/test_vibrato.py b/test/src/unittest/tonal/test_vibrato.py
new file mode 100644
index 000000000..0abcd564a
--- /dev/null
+++ b/test/src/unittest/tonal/test_vibrato.py
@@ -0,0 +1,113 @@
+#!/usr/bin/env python
+
+# Copyright (C) 2006-2016  Music Technology Group - Universitat Pompeu Fabra
+#
+# This file is part of Essentia
+#
+# Essentia is free software: you can redistribute it and/or modify it under
+# the terms of the GNU Affero General Public License as published by the Free
+# Software Foundation (FSF), either version 3 of the License, or (at your
+# option) any later version.
+#
+# This program is distributed in the hope that it will be useful, but WITHOUT
+# ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
+# FOR A PARTICULAR PURPOSE.  See the GNU General Public License for more
+# details.
+#
+# You should have received a copy of the Affero GNU General Public License
+# version 3 along with this program. If not, see http://www.gnu.org/licenses/
+
+
+
+from essentia_test import *
+from numpy import sin, float32, pi, arange, mean, log2, floor, ceil
+
+class TestVibrato(TestCase):
+
+    def testEmpty(self):
+        vibrato, extent = Vibrato()([])
+        self.assertEqual(vibrato.size, 0)
+        self.assertEqual(extent.size, 0)
+
+    def testZero(self):
+        vibrato, extent = Vibrato()([0])
+
+        self.assertEqualVector(vibrato, [0.])
+        self.assertEqualVector(extent, [0.])
+
+    def testOnes(self):
+        vibrato, extent = Vibrato()([1]*1024)
+
+        self.assertEqualVector(vibrato, [0.]*1024)
+        self.assertEqualVector(extent, [0.]*1024)
+
+
+    def testNegativeInput(self):
+        # Negative vlues should be set to 0
+        vibrato, extent = Vibrato()([-1]*1024)
+
+        self.assertEqualVector(vibrato, [0.]*1024)
+        self.assertEqualVector(extent, [0.]*1024)    
+
+    def testInvalidParam(self):
+        self.assertConfigureFails(Vibrato(), { 'maxExtend':    -1 })
+        self.assertConfigureFails(Vibrato(), { 'maxFrequency': -1 })
+        self.assertConfigureFails(Vibrato(), { 'minExtend':    -1 })
+        self.assertConfigureFails(Vibrato(), { 'minFrequency': -1 })
+        self.assertConfigureFails(Vibrato(), { 'sampleRate':   -1 })
+
+    def testSyntheticVibrato(self):
+        fs = 100  #Hz
+        f0 = 100  #Hz
+        extent = 5  #Hz
+        vibrato = 5 #Hz
+
+        x = [f0] * 1024 + extent * sin(2 * pi * vibrato * arange(1024) / fs)
+
+        vibratoEst, extentEst = Vibrato(sampleRate=fs)(x.astype(float32))
+
+        self.assertAlmostEqual(vibrato,mean(vibratoEst[3:-3]), 1)
+
+        extentCents = 1200*log2((f0+extent)/float(f0-extent))
+        self.assertAlmostEqual(extentCents, mean(extentEst[3:-3]), 1e-1)
+
+    def testFrequencyDetenctionThreshold(self):
+        #  Vibrato Min and Max default values are 3 and 8Hz so
+        #  this values shouldn't be detected.
+
+        fs = 100  #Hz
+        f0 = 100  #Hz
+        extent = 5  #Hz
+        vibrato = 3 #Hz
+        x = [f0] * 1024 + extent * sin(2 * pi * vibrato * arange(1024) / fs)
+
+        vibratoEst, extentEst = Vibrato(sampleRate=fs)(x.astype(float32))
+        self.assertEqual(0, vibratoEst.all())
+
+        vibrato = 9 #Hz
+        x = [f0] * 1024 + extent * sin(2 * pi * vibrato * arange(1024) / fs)
+        vibratoEst, extentEst = Vibrato(sampleRate=fs)(x.astype(float32))
+        self.assertEqual(0, vibratoEst.all())
+
+
+    def testExtendDetenctionThreshold(self):
+        #  Extend Min and Max default values are 50 and 250 cents so
+        #  this values  shouldn't be detected.
+        fs = 100  #Hz
+        f0 = 100  #Hz
+        extent = ceil(f0 * (2**(250/1200.) -1) / (2**(250/1200.) + 1))
+        vibrato = 5 #Hz
+        x = [f0] * 1024 + extent * sin(2 * pi * vibrato * arange(1024) / fs)
+        vibratoEst, extentEst = Vibrato(sampleRate=fs)(x.astype(float32))
+        self.assertEqual(0, vibratoEst.all())
+
+        extent = floor(f0 * (2**(50/1200.) -1) / (2**(50/1200.) + 1))
+        x = [f0] * 1024 + extent * sin(2 * pi * vibrato * arange(1024) / fs)
+        vibratoEst, extentEst = Vibrato(sampleRate=fs)(x.astype(float32))
+        self.assertEqual(0, vibratoEst.all())
+
+
+suite = allTests(TestVibrato)
+
+if __name__ == '__main__':
+    TextTestRunner(verbosity=2).run(suite)
\ No newline at end of file